The first six digits are card BIN, which is used to identify the issuing bank; After that, it is the number set by the bank itself; The last bit is the verification bit, which is calculated by all the previous numbers;

The part set by the bank itself generally starts with the number of the issuing branch, which is the internal number of the bank. Different banks are different.

Example:

Work 955880430 1 00 xxxxxxxx 955880 is the number 4301of the debit cards of BIN and ICBC. Except the last number, all the numbers in the middle are serial numbers.

Build 436742 13750 1 xxxxx436742bin, CCB debit card,137 Nanjing 501branch number, except for the last one, all the middle ones are serial numbers.

For a passbook, it is usually the branch number at the beginning, followed by the branch number, followed by the category change number, followed by the serial number, and the last digit is the verification bit.

Example:

Work 43010286 16xxxxxxxxx 4301Nanjing 0286 a certain outlet16 is a regular all-in-one machine.

Set up13750 1 998xxxxxxxx137 Nanjing 501998 all-in-one machine at a certain outlet.

However, not every bank necessarily meets this arrangement.

For example, some debit cards of joint-stock commercial banks with 16 digits have no branch number.

But it's basically like this.